Developing unit and image forming apparatus having the same

ABSTRACT

A developing unit to deliver developer in various directions or a predetermined direction, and an image forming apparatus having the same. The developing unit includes a developer housing and a delivery unit to provide the developer with a delivery force via rotation thereof. The developer housing includes a protrusion to interfere with the delivery unit during rotation of the delivery unit, so as to change a developer delivery direction. The delivery unit includes an elastic delivery member and in turn, the delivery member includes a plurality of delivery elements to interfere with the protrusion. The developer delivery direction may be changed variously by changing positions of the delivery element and the protrusion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(a) from KoreanPatent Application No. 2009-0088543, filed on Sep. 18, 2009 in theKorean Intellectual Property Office, the disclosure of which isincorporated herein by reference.

BACKGROUND

1. Field of the Invention

Embodiments of the present general inventive concept relate to adeveloping unit to deliver developer in a predetermined direction and animage forming apparatus having the same.

2. Description of the Related Art

Generally, image forming apparatuses are devised to form an image on aprinting medium according to inputted image signals. Examples of imageforming apparatuses include printers, copiers, facsimiles, and so-calledmulti-functional devices that combine some of the functionalities of theaforementioned devices.

In operation of an image forming apparatus, light is irradiated to aphotosensitive body that has been charged with a predetermined electricpotential, so as to form an electrostatic latent image on a surface ofthe photosensitive body. As toner as developer is supplied to theelectrostatic latent image, a visible toner image is formed. The tonerimage formed on the photosensitive body is directly transferred to aprinting medium or is indirectly transferred to the printing medium byway of an intermediate transfer body. The transferred image is fused tothe printing medium via a fusing process.

The above-described printing process may need delivery of the developer.Conventionally, delivery of the developer is accomplished by an agitatoror an auger.

However, the agitator or the auger is designed to deliver the developerin a direction perpendicular to a rotating axis thereof, having a limitin a delivery direction of the developer.

SUMMARY

Therefore, it is a feature and utility an aspect of the present generalinventive concept to provide a developing unit to deliver developer in apredetermined direction and an image forming apparatus having the same.

Additional features and utilities of the present general inventiveconcept will be set forth in part in the description which follows and,in part, will be obvious from the description, or may be learned bypractice of exemplary embodiments of the present general inventiveconcept.

Embodiments of the present general inventive concept provide adeveloping unit to deliver developer in various directions or in apredetermined direction and an image forming apparatus having the same.

Embodiments of the present general inventive concept may include adeveloping unit detachably mounted in an image forming apparatus and mayinclude a developing roller and a supply roller to supply developer to aphotosensitive body, the developing unit may further include a developerhousing to store the developer, and a delivery unit to deliver thedeveloper by being rotated in the developer housing, the delivery unitmay include a rotating shaft, and a delivery member coupled to therotating shaft and arranged to come into contact with the developer viarotation thereof, the delivery member may include at least one deliveryelement arranged in an axial direction of the rotating shaft, and thedeveloper housing including at least one protrusion arranged tointerfere with the at least one delivery element during rotation of thedelivery unit.

The at least one protrusion may be arranged at a position close to anyone side of the at least one delivery element on the basis of the centerof the at least one delivery element, so as to cause bending of a sideportion of the at least one delivery element.

The at least one protrusion may be arranged close to a left side of asurface of the at least one delivery element so as to come into contactwith the at least one delivery element when the surface of the at leastone delivery element is intended to face a direction deflected leftwardfrom a rotation tangential direction of the delivery unit.

The at least one protrusion may be arranged close to a right side of asurface of the at least one delivery element so as to come into contactwith the at least one delivery element when the surface of the at leastone delivery element is intended to face a direction deflected rightwardfrom a rotation tangential direction of the delivery unit.

The at least one delivery element may be formed by dividing the deliverymember into a plurality of delivery elements, and the at least oneprotrusion may be arranged to correspond to the surface of the at leastone delivery element.

The at least one protrusion may include a plurality of protrusionsarranged in a line in an axial direction of the rotating shaft of thedelivery unit.

The at least one protrusion may include a plurality of protrusionsarranged in zigzags in an axial direction of the rotating shaft of thedelivery unit.

The delivery member may include an elastic thin film member.

An angle between the surface of the at least one delivery element andthe direction deflected from the rotation tangential direction of thedelivery unit may be an acute angle.

Embodiments of the present general inventive concept may include animage forming apparatus having a developer delivery system, thedeveloper delivery system may include a developer housing to store thedeveloper, and a delivery unit to deliver the developer by being rotatedin the developer housing, the delivery unit may include a rotatingshaft, and a delivery member coupled to the rotating shaft and adaptedto provide the developer with delivery force via rotation thereof, thedelivery member may include at least one delivery element arranged in anaxial direction of the rotating shaft, and the developer housing mayinclude a direction change element to change a direction of thedeveloper delivery force by causing the at least delivery element to bebent in a predetermined direction during rotation of the delivery unit.

The direction change element may include at least one protrusion formedin the developer housing.

The at least one protrusion may be arranged within a rotation radius ofthe at least one delivery element, so as to come into contact with theat least one delivery element.

The at least one protrusion may be arranged at a position to applydeformation force to the at least one delivery element, so as to allowan orientation direction of a surface of the at least one deliveryelement to be changed from a first direction as a rotation tangentialdirection of the delivery unit to a second direction as a predetermineddelivery force application direction.

Embodiments of the present general inventive concept may include adeveloper delivery system that may include a developer housing to storedeveloper, and a delivery unit to deliver the developer by being rotatedin the developer housing, the delivery unit may include a rotatingshaft, and a film member coupled to the rotating shaft and adapted topush and deliver the developer in a predetermined direction, the filmmember may include at least one delivery element arranged in an axialdirection of the rotating shaft, and the developer housing may includeat least one interference member formed in the developer housing andadapted to interfere with the at least one delivery element duringrotation of the delivery unit so as to change a developer pushdirection.

Embodiments of the present general inventive concept may include a wastedeveloper return unit that may include a waste developer housing intowhich waste developer is introduced, and a delivery unit to deliver thewaste developer by being rotated in the waste developer housing, thedelivery unit may include a rotating shaft, and a delivery membercoupled to the rotating shaft and adapted to push and deliver thedeveloper in a predetermined direction via rotation thereof, thedelivery member may include at least one delivery element arranged in anaxial direction of the rotating shaft, and the waste developer housingmay include at least one protrusion protruding from an inner surface ofthe waste developer housing and adapted to come into contact with the atleast one delivery element so as to change an orientation direction of asurface of the at least one delivery element.

Embodiments of the present general inventive concept further include adeveloping unit within an image forming apparatus including a developerhousing to store a developer, and a delivery unit to rotatably deliverthe developer along a developer delivery direction, wherein the deliveryunit further includes a rotating shaft and flexible driving memberattached thereto to direct the developer along the developer deliverydirection, and the developer housing further includes a plurality ofprotrusions along an inner surface thereof to provide multiple developerdelivery directions of the developer within the developer housing atseparate time intervals.

Embodiments of the present general inventive concept further include amethod of modifying developer delivery direction within a developer unitof an image forming apparatus including rotating a delivery unit with anelongated delivery member within a developer housing of the developerunit; and colliding the delivery member with at least one protrusionpositioned on an inner surface of the developer housing.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other features and utilities of the present generalinventive concept will become apparent and more readily appreciated fromthe following description of the exemplary embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a view illustrating an interior configuration of an imageforming apparatus according to an exemplary embodiment of the presentgeneral inventive concept;

FIG. 2 is a perspective view illustrating an exterior appearance of adeveloping unit;

FIG. 3 is a sectional view of the developing unit;

FIG. 4 is a perspective view illustrating an interior configuration of adeveloper housing;

FIG. 5 is a detailed view illustrating the interior of the developerhousing;

FIG. 6 is a detailed view illustrating a developer delivery system;

FIGS. 7A and 7B are views illustrating a mutual operational relationshipof a delivery element and a protrusion;

FIGS. 8A to 8C are conceptual views illustrating a developer deliverydirection based on positional relationship of the delivery element andthe protrusion;

FIG. 9 is a view illustrating a developer delivery system according toan exemplary embodiment of the present general inventive concept; and

FIG. 10 is a view illustrating a developer delivery system according toan exemplary embodiment of the present general inventive concept.

FIGS. 11A-11C are detailed views illustrating various positions of theprotrusions within the developer housing.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thepresent general inventive concept, examples of which are illustrated inthe accompanying drawings, wherein like reference numerals refer to likeelements throughout. The exemplary embodiments are described below inorder to explain the present general inventive concept by referring tothe figures.

FIG. 1 is a view illustrating an interior configuration of an imageforming apparatus according to an exemplary embodiment of the presentgeneral inventive concept. FIG. 2 is a perspective view illustrating anexterior appearance of a developing unit. FIG. 3 is a sectional view ofthe developing unit.

As illustrated in FIG. 1, the image forming apparatus 1 may include abody 10 defining an exterior appearance of the image forming apparatus1, a supply unit 20 to supply paper P stored therein, a developing unit30 to form a developer image on the paper P supplied via the supply unit20, a Light Scanning Unit (LSU) 40 to form an electrostatic latent imageon a photosensitive body 31 of the developing unit 30, a fusing unit 50to fuse developer transferred to the paper P, a paper discharge unit 60to discharge the paper P, on which the image has been completely formed,out of the body 10, and a double-sided printing unit 70 to return thepaper P, on a surface of which the image has been completely formed, tothe developing unit 30.

The supply unit 20 may serve to supply the paper P to the developingunit 30, and may include a paper cassette 21 separably mounted to thebody 10, a knock-up plate 22 installed in the paper cassette 21 to loadthe paper P thereon, and a pickup roller 24 to pick up the paper S onthe knock-up plate sheet by sheet so as to transmit the paper P to thedeveloping unit 30. Feed rollers 11 may be installed in the body 10 todeliver the paper P picked up by the pickup roller 24 to the developingunit 30.

The light scanning unit 40 may irradiate light containing imageinformation to the photosensitive body 31, so as to form anelectrostatic latent image on the photosensitive body 31.

The fusing unit 50 may serve to fuse the developer image formed on thepaper P by applying heat and pressure to the paper P. The fusing unit 50may include a heating roller 52 having a heater 51, and a press roller53 to press the paper P using the heating roller 52. As the paper Preceives heat and pressure while passing through a gap between theheating roller 52 and the press roller 53, the developer image on thepaper P may be fused to the paper P.

The paper discharge unit 60 may include a paper discharge roller 62 andserve to discharge the paper P, having passed through the fusing unit50, out of the body 10.

The double-sided printing unit 70 may serve to return the paper P, on asurface of which the image has been completely formed, to the developingunit 30, so as to enable printing of both surfaces of the paper P. Thedouble-sided printing unit 70 may include a double-sided printing guide71 to define a return path of the printed paper P, and a series ofreturn rollers 72 installed on the return path of the printed paper P todeliver the paper P.

The developing unit 30 may form the developer image on the paper Pdelivered from the paper supply unit 20. The developing unit 30, asillustrated in FIGS. 2 and 3, may include the photosensitive body 31 onthe surface of which the electrostatic latent image is formed by thelight scanning unit 40, a charging roller 32 to charge thephotosensitive body 31, a developing roller 33 to develop theelectrostatic latent image formed on the photosensitive body 31 into adeveloper image by supplying the developer to the photosensitive body31, a supply roller 34 to supply the developer to the developing roller33, a cleaning roller 35 to clean the charging roller 32, and a housing36 defining an exterior appearance of the developing unit 30. A transferroller 12 may be installed in the body 10 to transfer the developerimage of the photosensitive body 31 to the paper P by pressing the paperP toward the photosensitive body 31.

A developer housing 37 to store the developer may be arranged in thedeveloping unit 30. The developer housing 37 may serve to store thedeveloper therein at normal times, and to supply the developer to thesupply roller 34 during a printing operation.

The developer housing 37 may include a first developer housing 38 inwhich a developer delivery system 100 according to the exemplaryembodiment of the present general inventive concept is provided, and asecond developer housing 39 to store the developer delivered from thefirst developer housing 38.

Hereinafter, the developer delivery system 100 will be described indetail.

FIG. 4 is a perspective view illustrating an interior configuration ofthe developer housing, FIG. 5 is a detailed view illustrating theinterior of the developer housing, FIG. 6 is a detailed view of thedeveloper delivery system, FIGS. 7A and 7B are views illustrating themutual operational relationship of a delivery element and a protrusion,and FIGS. 8A to 8C are conceptual views illustrating a developerdelivery direction based on positional relationship of the deliveryelement and the protrusion.

As illustrated in FIGS. 4 to 6, the developer delivery system 100 may beprovided in the first developer housing 38. The developer deliverysystem 100 may include the first developer housing 38 to store thedeveloper, and a delivery unit 110 to deliver the developer while beingrotated in the first developer housing 38. The width of the firstdeveloper housing is represented by 38W in FIG. 5 and the length of thefirst developer housing 38 is represented by 38L in FIG. 4.

The delivery unit 110 may include a rotating shaft 113 defining arotatable body of the delivery unit 110, and a delivery member 115rotatably coupled to the rotating shaft 113 and arranged to interferewith the developer via rotation thereof. The height of the deliverymember 115 is represented by 115H in FIG. 6 and the height of therotating shaft 113 is represented by 113H in FIG. 6

The rotating shaft 113 and the delivery member 115 may be arranged in alongitudinal direction of the developing unit 30. The delivery member115 is an elastic thin film member.

The delivery member 115 may include at least one delivery element 115 aarranged in an axial direction of the rotating shaft 113 with a heightof 115 aH, as illustrated in FIG. 6. The delivery element 115 a may beformed by dividing the delivery member 115 into a plurality ofindependently movable elements. The space in a longitudinal directionbetween delivery member 115 and delivery element 115 a is represented by160 in FIGS. 7A, 7B, and 8A-8C. A space 180, illustrated in FIG. 8A, mayexist between the delivery element 115 a and an inner surface of thefirst developer housing 38.

Specifically, although a part of the delivery member 115 is integrallycoupled to the rotating shaft 113, the remaining part of the deliverymember 115 used to directly apply delivery force to the developer isdivided to form the at least one independently movable delivery element115 a.

The first developer housing 38 may include at least one protrusion 130protruding from an inner surface of the first developer housing 38 andconfigured to come into contact with the at least one delivery element115 a during rotation of the delivery unit 110. The protrusion 130 maybe located within a rotation radius of the delivery element 115 a.

As illustrated in FIGS. 7A and 7B, when the at least one protrusion 130comes into direct contact with the at least one delivery element 115 a,the protrusion 130 may act to change a developer delivery direction.

After the delivery unit 110 begins to be rotated and before the deliveryelement 115 a comes into contact with the protrusion 130, a developerdelivery force direction may be applied in a first direction A as arotation tangential direction of the rotating shaft 113 of the deliveryunit 110. In this case, a surface of the delivery element 115 a facesthe first direction A as the rotation tangential direction of therotating shaft 113.

Then, when the delivery element 115 a comes into contact with andinterferes with the protrusion 130 arranged close to the left side ofthe surface of the delivery element 115 a via further rotation of thedelivery unit 110, the delivery element 115 a may elastically deform sothat a left portion of the surface of the delivery element 115 a isbent, causing the surface of the delivery element 115 a to face a seconddirection B that is deflected leftward from the first direction A. Thesecond direction B is a direction along which a user may intend to applya developer delivery force. In addition, an angle between the firstdirection A and the second direction B may be an acute angle θ.

Although FIGS. 7A and 7B illustrate an example wherein the protrusion130 is arranged close to the left side of the surface of the deliveryelement 115 a, on the contrary, the protrusion 130 may be arranged closeto the right side of the surface of the delivery element 115 a asillustrated in FIG. 8A. In this case, a right portion of the mainsurface of the delivery element 115 a is bent, causing the main surfaceof the delivery element 115 a to face a rightward deflected direction C.

As illustrated in FIG. 8B, one or more protrusions 130 may be aligned ina line in the axial direction of the rotating shaft 113 of the deliveryunit 110. In this case, the main surface of the delivery element 115 afaces the leftward deflected direction B and thus, developer deliveryforce acts in the leftward deflected direction B throughout the axialdirection of the rotating shaft 113. Also, illustrated in FIGS. 8B and8C is the height 130H of the protrusions 130 and the width 130W of theprotrusions 130. Although the protrusions 130 illustrated in the figureshave a diameter as a width, the protrusions may comprise of othershapes, such as rectangles.

As illustrated in FIG. 8C, one or more protrusions 130′ and 130″ may bearranged in zigzags in the axial direction of the rotating shaft 113 ofthe delivery unit 110. In this case, the developer delivery directionmay be changed with a time interval. The protrusion 130′ at a rearsurface of the delivery member 115 may first interfere with a deliveryelement 115 a′, temporarily changing the developer delivery direction(from a direction A′ to a direction B′). Subsequently, the protrusion130″ at a front surface of the delivery member 115 may interfere with adelivery element 115 a″, changing the developer delivery direction (froma direction A″ to a direction B″).

Considering the above principle described with reference to FIGS. 7A to7C in conjunction with the delivery direction illustrated in FIGS. 4 to6 according to the exemplary embodiment of the present general inventiveconcept, the developer may move between the first developer housing 38and the second developer housing 39 through a front space 37 a and arear space 37 b of the developer housing 37. The developer may bedelivered in a direction “X” through the front space 37 a and deliveredin a direction “Y” through the rear space 37 b.

The width of the second developer housing 39 is represented by 39W inFIG. 5 and the length of the second developer housing 39 is representedby 39L in FIG. 4. A height of the first developer housing 38 isrepresented by 38H in FIG. 5, and a height of the second developerhousing 39 is represented by 39H in FIG. 5.

Now, the delivery of the developer through the rear space 37 b will bedescribed in more detail with reference to FIG. 6. Assuming that thedelivery unit 110 may be rotated clockwise, the developer delivery forcedirection may be changed from the rotation tangential direction of thedelivery unit 110 to the direction “Y” via mutual interference betweenthe at least one protrusion 130 and the delivery element 115 a.Accordingly, the developer in the first developer housing 38 may bedelivered to the second developer housing 39 through the rear space 37b. As a delivery auger 39 a delivers the developer within the seconddeveloper housing 39, consequently, the developer may be supplied to thesupply roller 34, the developing roller 33, and the photosensitive body31.

Hereinafter, an exemplary embodiment of the present general inventiveconcept will be described with reference to the accompanying drawing.

FIG. 9 is a view illustrating a developer delivery system according toan exemplary embodiment of the present general inventive concept.

A developer delivery system 200 according to the present exemplaryembodiment may include a developer housing 250 having a bottom outlethole 255, and a delivery unit 210 to deliver the developer.

The delivery unit 210 may include a rotating shaft 213, and a deliverymember 215 rotatably coupled to the rotating shaft 213 and arranged tocome into contact with the developer via rotation thereof. The deliverymember 215 may be divided into a plurality of delivery elements 215 a,215 a′, and 215 a″ arranged in an axial direction.

The developer housing 250 may include protrusions 230 and 230′ arrangedto interfere with the delivery elements 215 a and 215 a″ arranged ataxially opposite sides of the rotating shaft 213 of the delivery unit210.

The delivery element 215 a at the left side of the delivery unit 210 mayinterfere with the protrusion 230 arranged close to the right side of asurface of the delivery element 215 a. The delivery element 215 a″ atthe right side of the delivery unit 210 may interfere with theprotrusion 230′ arranged close to the left side of a surface of thedelivery element 215 a″. The delivery element 215 a′ at the center ofthe delivery unit 210 may rotate without interference with theprotrusions 230 and 230′.

Accordingly, the delivery element 215 a at the left side of the deliveryunit 210 may cause a rightward developer delivery force, and thedelivery element 215 a″ at the right side of the delivery unit 210 maycause a leftward developer delivery force. The delivery element 215 a″at the center of the delivery unit 210 may cause forward developerdelivery force.

Thereby, the developer in the developer housing 250 may be deliveredthrough the outlet hole 255.

The developer delivery system 200 according to the exemplary embodimentof FIG. 9 may be directly applied to the second developer housing 39 ofFIGS. 1 to 6.

Hereinafter, a further exemplary embodiment of the present generalinventive concept will be described with reference to the accompanyingdrawing.

FIG. 10 is a view illustrating a developer delivery system according toa further exemplary embodiment of the present general inventive concept.

A waste developer delivery system 300 may include a delivery unit 310 todeliver waste developer and a waste developer housing 350 to store thewaste developer.

The waste developer housing 350 according to the exemplary embodiment ofFIG. 10 generally has a bar shape, and may include a waste developerinlet hole 355 formed in one end thereof. Once waste developer isintroduced through the waste developer inlet hole 355, the wastedeveloper may be delivered in a longitudinal direction, thereby beingdelivered to a space S defined in the other end of the waste developerhousing 350.

The delivery unit 310 may include a rotating shaft 313, an auger 317coupled to a part of the rotating shaft 313, and a delivery member 318coupled to the remaining part of the rotating shaft 313.

The auger 317 may serve to deliver the waste developer introducedthrough the waste developer inlet hole 355 to the space S. The deliverymember 318 may be divided into a plurality of delivery elements 318 a.

The waste developer housing 350 may include a plurality of protrusions330 arranged close to the left side of a surface of each deliveryelement 318 a, respectively.

The waste developer introduced through the waste developer inlet hole355 may reach an entrance of the space S via operation of the auger 317.As the delivery member 318 is rotated clockwise, a developer deliveryforce direction may be changed leftward from a rotation tangentialdirection of the delivery unit 310 via interference between therespective delivery elements 318 a and the protrusions 330.

In this manner, the waste developer may be uniformly deliveredthroughout the empty space S.

With the use of the developer delivery system and the waste developerdelivery system as described above, the developer and the wastedeveloper may be delivered even to a space that conventionally hasdifficulty in delivery.

FIGS. 11A through 11C further define the placement of the protrusions130 within the first developer housing 38. In particular, FIG. 11Aillustrates the protrusions 130 in alignment with each other as well asaligned with the rotational axis of the delivery member 115. Eachprotrusion 130 is in contact with the delivery elements 115A on thedelivery member 115, but each delivery element 115A is not yet bent.

FIG. 11B illustrates the protrusions 130 separated from one another inequal distances in the rotational direction of the delivery member 115.In particular, each protrusion 130 is separated from the next closestprotrusion 130 by a distance of AA. The protrusions 130 are spaced apartfrom each other in a lengthwise direction by a distance XX. Further,FIG. 11B also illustrates a protrusion 130 contacting the deliveryelement 115 a, wherein the delivery element 115 a is fully extended atan angle β.

FIG. 11C illustrates the protrusions separated from one another innon-equal distances in the rotational direction of the delivery member115. In particular, two protrusions are distanced from each other by adistance of AA while another distance BB represents a distance betweentwo other protrusions. The distance between protrusions 130 both in therotational direction of the delivery member 115 and the lengthwisedirection of the delivery member 115, as illustrated with the arrow inFIG. 11C, may vary. For example, FIG. 11C illustrates that the distancedistances XX and YY in the lengthwise direction between protrusions 130are not equal. Also illustrated in FIG. 11C is the delivery element 115a fully extended at angle β as well as not

As is apparent from the above description, in a developing unit and animage forming apparatus having the same according to the exemplaryembodiment of the present general inventive concept, a delivery memberto deliver developer may be deformed when coming into contact with aprotrusion of a developer housing, enabling delivery of the developer ina predetermined direction.

Furthermore, the developer may be delivered in various directions or apredetermined direction.

Although a few exemplary embodiments of the present general inventiveconcept have been illustrated and described, it would be appreciated bythose skilled in the art that changes may be made in these exemplaryembodiments without departing from the principles and spirit of thegeneral inventive concept, the scope of which is defined in the claimsand their equivalents.

What is claimed is:
 1. A developing unit detachably mounted in an imageforming apparatus and comprising: a developing roller and a supplyroller to supply developer to a photosensitive body, the developing unitfurther comprising: a developer housing to store the developer; and adelivery unit to deliver the developer by being rotated in the developerhousing, wherein the delivery unit includes a rotating shaft, and adelivery member coupled to the rotating shaft and arranged to come intocontact with the developer via rotation thereof, wherein the deliverymember includes at least one delivery element arranged in an axialdirection of the rotating shaft, and wherein the developer housingincludes at least one protrusion arranged to interfere with the at leastone delivery element along an axial direction of the rotating shaftduring rotation of the delivery unit to form an angle with the axialdirection of the rotating shaft.
 2. The developing unit according toclaim 1, wherein the at least one protrusion is arranged at a positionclose to any one side of the at least one delivery element on the basisof the center of the at least one delivery element, so as to causebending of a side portion of the at least one delivery element.
 3. Thedeveloping unit according to claim 2, wherein the at least oneprotrusion is arranged close to a left side of a surface of the at leastone delivery element so as to come into contact with the at least onedelivery element when the surface of the at least one delivery elementis intended to face a direction deflected leftward from a rotationtangential direction of the delivery unit.
 4. The developing unitaccording to claim 2, wherein the at least one protrusion is arrangedclose to a right side of a surface of the at least one delivery elementso as to come into contact with the at least one delivery element whenthe surface of the at least one delivery element is intended to face adirection deflected rightward from a rotation tangential direction ofthe delivery unit.
 5. The developing unit according to claim 3 or 4,wherein an angle between the surface of the at least one deliveryelement and the direction deflected from the rotation tangentialdirection of the delivery unit is an acute angle.
 6. The developing unitaccording to claim 1, wherein: the at least one delivery element isformed by dividing the delivery member into a plurality of deliveryelements; and the at least one protrusion is arranged to correspond tothe surface of the at least one delivery element.
 7. The developing unitaccording to claim 6, wherein the at least one protrusion includes aplurality of protrusions arranged in a line in an axial direction of therotating shaft of the delivery unit.
 8. The developing unit according toclaim 6, wherein the at least one protrusion includes a plurality ofprotrusions arranged in zigzags in an axial direction of the rotatingshaft of the delivery unit.
 9. The developing unit according to claim 1,wherein the delivery member includes an elastic thin film member.
 10. Animage forming apparatus having a developer delivery system wherein thedeveloper delivery system comprises: a developer housing to store adeveloper, and a delivery unit to deliver the developer by being rotatedin the developer housing, wherein the delivery unit comprises: arotating shaft, and a delivery member coupled to the rotating shaft andadapted to provide the developer with delivery force via rotationthereof, wherein the delivery member comprises: at least one deliveryelement arranged in an axial direction of the rotating shaft, andwherein the developer housing comprises: a direction change element tochange a direction of the developer delivery force by causing the atleast delivery element to be bent along the axial direction in apredetermined direction during rotation of the delivery unit, thepredetermined direction of the bent delivery element having an anglewith the axial direction.
 11. The image forming apparatus according toclaim 10, wherein the direction change element includes at least oneprotrusion formed in the developer housing.
 12. The image formingapparatus according to claim 11, wherein the at least one protrusion isarranged within a rotation radius of the at least one delivery element,so as to come into contact with the at least one delivery element. 13.The image forming apparatus according to claim 12, wherein the at leastone protrusion is arranged at a position to apply deformation force tothe at least one delivery element, so as to allow an orientationdirection of a surface of the at least one delivery element to bechanged from a first direction as a rotation tangential direction of thedelivery unit to a second direction as a predetermined delivery forceapplication direction.
 14. A developer delivery system comprising: adeveloper housing to store developer; and a delivery unit to deliver thedeveloper by being rotated in the developer housing, wherein thedelivery unit includes a rotating shaft, and a film member coupled tothe rotating shaft and adapted to push and deliver the developer in apredetermined direction, wherein the film member includes at least onedelivery element arranged in an axial direction of the rotating shaft,and wherein the developer housing includes at least one interferencemember formed in the developer housing and adapted to interfere with theat least one delivery element along an axial direction of the rotationshaft during rotation of the delivery unit so as to change a developerpush direction having an angle with the axial direction of the rotationshaft.
 15. A waste developer return unit comprising: a waste developerhousing into which waste developer is introduced; and a delivery unit todeliver the waste developer by being rotated in the waste developerhousing, wherein the delivery unit includes a rotating shaft, and adelivery member coupled to the rotating shaft and adapted to push anddeliver the developer in a predetermined direction via rotation thereof,wherein the delivery member includes at least one delivery elementarranged in an axial direction of the rotating shaft, and wherein thewaste developer housing includes at least one protrusion protruding froman inner surface of the waste developer housing and adapted to come intocontact with the at least one delivery element so as to change anorientation direction of a surface of the at least one delivery elementalong the axial direction of the rotating shaft, the orientationdirection having an angle with the axial direction of the rotatingshaft.
 16. A developing unit detachably mounted in an image formingapparatus and adapted to supply developer to a photosensitive body, thedeveloping unit comprising: a developer housing to store developer; anda drive shaft provided in the developer housing; at least one deliveryelement installed to the drive shaft and adapted to agitate or deliverthe developer upon receiving drive force from the drive shaft; and atleast one protrusion provided in the developer housing to interfere withthe at least one delivery element so as to allow the at least onedelivery element to be oriented in a predetermined direction along thedrive shaft during rotation of the at least one delivery element, thepredetermined direction having an angle with the drive shaft.
 17. Adeveloping unit within an image forming apparatus comprising: adeveloper housing to store a developer; and a delivery unit to rotatablydeliver the developer along a developer delivery direction, wherein thedelivery unit further comprises: a rotating shaft and flexible drivingmember attached thereto to direct the developer along the developerdelivery direction, and the developer housing further comprises: aplurality of protrusions along an inner surface thereof to providemultiple developer delivery directions of the developer along an axialdirection of the rotating shaft within the developer housing at separatetime intervals to have an angle with the axial direction of the rotatingshaft.
 18. The developing unit of claim 17, wherein the plurality ofprotrusions each collide with the flexible driving member at separatetime intervals during rotation of the driving member.
 19. The deliveryunit of claim 17, wherein the plurality of protrusions each collide withthe flexible driving member at different locations thereon, causingmultiple developer delivery directions of the developer within thedeveloper housing.
 20. A method of modifying developer deliverydirection within a developer unit of an image forming apparatuscomprising: rotating a delivery unit with an elongated delivery memberwithin a developer housing of the developer unit; and colliding thedelivery member with at least one protrusion positioned on an innersurface of the developer housing such that the delivery member is bentalong the an axial direction of the delivery unit in a direction havingan angle with the axial direction of the delivery unit.
 21. The methodof claim 20, wherein a plurality of protrusions are aligned along anaxis parallel with the rotational axis of the delivery unit on the innersurface of the developer housing.
 22. The method of claim 21, whereinthe delivery member further comprises a plurality of delivery elementsspaced apart from each other and elastically deformable upon collidingwith the plurality of protrusions.